Python Quick Start Guide

Author: Callum Smith, Oct 2025 (last updated: Oct 2025)

Introduction

Python is a powerful, easy-to-learn programming language widely used in science, data analysis, web development, automation, and more. This guide will help beginners get started with Python, focusing on best practices for installation, environment management, and basic usage. For scientific and data work, using Conda (or Mamba) is highly recommended—see the Conda Setup Guide for details.

Opening a Terminal

To use Python and Conda/Mamba, you'll need to open a terminal (command line window) on your computer:

  • Windows:
    • If you have Windows Subsystem for Linux (WSL) installed, open the Start menu, search for "WSL" or your chosen Linux distribution (e.g., Ubuntu), and click to open a Linux terminal.
    • Alternatively and more commonly, use MobaXterm: install it, then open MobaXterm and start a local terminal session.
  • Mac:
    • Open the Terminal app (find it in Applications > Utilities, or search for "Terminal" in Spotlight).
  • Linux:
    • Open your system's Terminal app (often found in the applications menu, or use Ctrl+Alt+T as a shortcut).

Once your terminal is open, you can follow the steps below to install Python, set up environments, and run code. Python stays installed, so you only need to setup once.

Why Use Python?

  • Simple, readable syntax
  • Large ecosystem of libraries for every purpose
  • Excellent for beginners and experts alike
  • Strong community support

While you can install Python directly from python.org, the best way for scientific work is to use Conda or Mamba. This lets you easily manage multiple Python versions and install packages without conflicts.

See the Conda Setup Guide for step-by-step instructions.

Step 2: Create a Python Environment

Environments keep your projects isolated, so packages for one project don’t interfere with another.

mamba create -n mypython python=3.11
mamba activate mypython

Step 3: Install Packages

Use Mamba (or Conda) to install packages from the conda-forge channel. This ensures compatibility and avoids dependency issues.

mamba install numpy pandas matplotlib

Step 4: Write and Run Python Code

You can write Python code in a text editor (like VS Code) and run it from the terminal:

python myscript.py

Or use interactive notebooks (Jupyter) for data analysis:

mamba install jupyterlab
jupyter lab

Step 5: Learn the Basics

A brilliant and comprehensive guide to Python is hosted by Arc at Leeds.

Best Practices

  • Always use environments for your projects
  • Prefer conda-forge for package installs
  • Read error messages—they help you debug!

Troubleshooting

  • If you have issues with packages, check you’re using conda-forge and not mixing channels
  • If Python isn’t found, make sure your environment is activated
  • For help, search error messages or ask the community

Python is a great language for learning and doing real-world work. With Conda/Mamba and conda-forge, you’ll avoid most installation headaches and be ready to explore!